Honeybee lifespan shorten by half as it was 50 years ago

The lifespan of honeybees in laboratory conditions in the USA has decreased by half since the 1970s. This indicates that colony losses may not only be attributed to environmental factors like pesticides and food sources, but also to genetics. A study by the University of Maryland revealed that the median lifespan of worker western honeybees that lived their entire adult life in a controlled environment was 34.3 days 50 years ago, but now it has declined to 17.7 days.

Initially, the study aimed to explore the effects of supplementing lab-kept bees with plain water along with their regular diet of sugar water. However, upon examining previous research on similar topics, the researchers noted a consistent decline in bee lifespan from the 1970s to the present day. This trend was also reflected in the lifespan of the bees in the team's cages. Strangely, the mortality rate of lab-reared honeybees has doubled since the implementation of protocols for their breeding in the 2000s. This finding suggests that solutions to the problem of reduced colony lifespan, which beekeepers are increasingly facing, may lie in the bees themselves.

Since 2006, researchers began to observe higher rates of colony loss due to the emergence of colony collapse disorder, which caused widespread bee deaths in the US. Although the disorder decreased after 2008, the rate of colony loss has continued to surpass what beekeepers consider financially feasible, and the underlying causes of this trend are unclear.

According to the study, if the lifespan of a single bee were to decline by half, the annual loss rate of the colony would be 33%, a percentage that corresponds well with the loss rates observed by beekeepers during overwintering and yearly, which vary between 30% and 40%. The research offers a valuable model for examining how recognized environmental factors, such as pathogens, parasites, pesticides, and insufficient nourishment, collaborate with bee genetics to manage lifespan.